Hydraulic lift truck scales



1955 D. w. PHILBROOK HYDRAULIC LIFT TRUCK SCALES 5 Sheets-Sheet 1 Filed Dec. 10, 1953 EWE) INVENTOR. 4 DONALD w. /wwmox Nov. 1, 1955 D. w. PHILBROOK HYDRAULIC LIFT TRUCK SCALES 3 Sheets-Sheet 2 Filed Dec. 10, 1953 INVENTOR. DONAL D M. P/l/L'BFOOA QMZM ATTORNEY 1, 1955 D. w. PHILBROOK 2,722,411

HYDRAULIC LIFT TRUCK SCALES Filed Dec. 10, 1955 3 Sheets-Sheet 3 INVEN TOR. OONA L 0 m PH/z 3900/1 ron/s2 United States Patent HYDRAULIC LIFT TRUCK SCALES Donald W. Philbrook, Oakland, Calif. Application December 10, 1953, Serial No. 397,390 3 Claims. (Cl. 265-40) The present invention relates to an hydraulic lift truck scales and it consists in the combinations, constructions and arrangements of parts herein described and claimed.

Generally there is provided an attachment for a conventional hydraulic lift truck which comprises essentially a pair of pistons each attached to one end of a multiple link chain which is, in turn, connected to the conventional lifting fork over a pulley. The piston is vertically slidable in a cylinder in each'case and the cylinders are attached to a permanent part of the conventional mast. Fluid in the cylinders is compressed by the load upon the forks and is translated into a reading upon a pressure operated meter thus giving at a glance the weight of material placed upon the fork at any given time.

It is accordingly an object of the invention to provide a novel weighing attachment for a conventional hydraulic lift truck.

Another object of the invention is to provide a device of the character set forth which is simple in construction, inexpensive to manufacture and yet effective and efiicient in use.

A further object of the invention is to provide, in a device of the character set forth, novel mountings for cylinders and pistons forming parts of the invention.

Another object of the invention is to provide, in a device of the character set forth, novel means for operating a meter forming a part of the invention.

Other and further objects of the invention will become apparent from a reading of the following specification taken in conjunction with the drawings, in which:

Figure l is a side elevational view of an embodiment of the invention mounted upon the conventional hydraulic lifting apparatus,

Figure 2 is a fragmentary front elevational view of the apparatus shown in Figure 1,

Figure 3 is a fragmentary rear elevational view of Figure 2,

Figure 4 is a fragmentary sectional view taken along line 44 of Figure 2,

Figure 5 is a fragmentary elevational view similar to Figure 2 but shown somewhat enlarged to illustrate certain details of the invention,

Figure 6 is a fragmentary sectional view taken along line 66 of Figure 5,

Figure 7 is a fragmentary sectional view taken along line 7-7 of Figure 5,

Figure 8 is an elevational view, partly broken away, of an anchor, cylinder, piston and link, all forming parts of the invention,

Figure 9 is a sectional view taken line 9-9 of Figure 8,

Figure 10 is a reduced side elevational view of Figure 8, and

Figure 11 is an enlarged elevational view of a meter forming a part of the invention.

Referring more particularly to the drawing, there is shown therein a hydraulic lift truck comprising a platsubstantially along form 10 having front supporting wheels 11 and rear 2 vdirzigible wheels 12 and provided with a conventional operators seat 13 and steering wheel 14. To the forward end of the platform 10 there is vertically aflixed a ,mast comprising a pair of parallel spaced upright members 15 which are interconnected at their upper ends by across bar 16 and interconnected further adjacent the upper ends by means of a cross bar 16a. A vertically slidable member is generally indicated at 16b and comprises a cross bar 17 having a pair of verticallydependent standards 17a which are slidably mounted each immediately inwardly of one of the members 15. .A cylinder 18 is affixed in conventional manner to the forward end of the platform 10 and has extending upwardly therefrom a piston rod 19 whose upper end is aifixed to the cross bar 17, by means of a hub 20.

A pulley 21 is carried at either side of the hub 15 and each pulley has entrained thereOver a multi-link chain 22 one end of which in each case is attached to a carriage 23 which has forwardly projecting from the bottom thereof a plurality of lifting forks 24.

The cylinder 18 is supplied with hydraulic fluid by means of a pump (not shown) operated by an internal combustion engine 25 carried rearwardly of the operators seat 13. The masts are interconnected by a pair of diagonal braces 26. The other ends of the chains'22 are connected to cylinder assemblies generally indicated at 27 and shown in greater detail in Figures 8 to 10, inclusive. Each of the cylinder assemblies consists of an anchor 28 which is affixed atop the member 16a .and which is provided with two pairs of ears 29 upon its upper side. The anchor 28 is provided with a plurality of transverse openings 30 whereby the same may be bolted or otherwise affixed to the member 16a.

A bracket 31 of inverted U-shape is provided with reduced lower ends for its leg portions, as indicated at 32, and these reduced portions 32 are each mounted between one of the pairs of ears 29. A pin 33 extends through the cars 29 and reduced portions 32 and is provided with cotter keys 34 for retaining the same in proper position. Mounted within the bracket 31 is a cylinder 35 provided at its upper end with a vertical passageway 36 through which extends a rod 37 whose lower end is enlarged to form a piston 38. The passageway 36 is provided with a pair of annular grooves 37a for the reception therein of suitable rings and the piston 38 is provided with a pair of annular grooves 39, likewise for the reception of suitable piston rings. The rod 37 extends through the passageway 36 and through an opening 40 in the apex portion of the bracket 31 and extends into an opening provided between a pair of ears 41 formed in the lower end of a link 42 whose upper end is provided with a plurality of upwardly extending ears 43. The upper end of the rod 37 and the ears 41 are hingedly interconnected by means of a pin 44 each end of which is provided with a cotter key 45 to retain the same in position. A pin 46 extends through all of the cars 43 and through the ends of the adjacent chain 22 whereby to link the same thereto and each end of the pin 46 is likewise provided with a cotter key 47. Fluid 48 is positioned in the cylinder 35 above the piston 38 and each cylinder 35 is provided with a tube 49 which connects with the fluid 48 within the cylinder 35 at one of its ends and both of which connect with a fitting 50 which, in turn, has connected thereto a tube 51 whose other end is connected to a meter 52 which is mounted preferably upon the area where the diagonal brace members 26 cross. The meter 52 is provided with a pointer 53 and suitable indicia 54 which indicates pounds per square inch pressure.

In operation, it will be apparent that the cylinder 18 and its allied structure merely act to lift a load which may be placed upon the forks 24. However, when such a load is duly placed upon the forks 24 and the load lifted, the stress upon the chains 22 is translated to an upward force upon the piston 38 which, in turn, is translated to movement of the pointer 53 upon the meter 52 through the medium of the fluid 48 transmitting its pressure through the tubes 49 and tube 51 to the meter 52. Such pressure indications may be translated by a chart or other means to indicate exactly the weight of the articles being lifted by the forks 24 so that when a truck is being loaded by the lifting apparatus above described, an accurate check may be kept at all times so as not to overload the truck and thus keep the latter within the legal limits of the various States through which the trucks may have to travel.

While but one form of the invention has been shown and described herein, it will be readily apparent to those skilled in the art that many minor modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. An apparatus of the character described comprising, in combination with a lift truck having a platform, a mast affixed to said platform, a vertically movable member slidable in said mast, a lifting fork carried by said movable member, a hydraulic jack interconnecting the movable member and the platform, rollers carried at the upper end of the movable member, chains entrained over said rollers and each interconnecting said fork and said mast, the provision of a meter carried by said truck, and hydraulic means in the connections of the chains to said mast whereby to indicate the weight of articles carried by said fork, said means including a cross bar afiixed to said mast, a pair of anchors affixed to said cross bar,

upwardly extending pairs of ears afiixed to each of said anchors, an inverted bracket for each of said anchors each having a bight portion provided with a central opening and each having its leg portions pivotally connected to a pair of said ears, a cylinder mounted within each of said brackets, a piston in each of said cylinders, a piston rod extending upwardly through each cylinder and adjacent opening from each of said pistons, a link pivoted to the upper end of each rod and means for pivotally connecting each of said links with an adjacent chain end.

2. A device as defined in claim 1 wherein the last mentioned means comprises a plurality of upwardly extending fingers formed at the upper edge of said link, each adjoining pair of fingers being adapted to pivotally receive therebetween a portion of said adjacent chain end.

3. A device as defined in claim 1 wherein there is provided a fitting, a pair of tubes each interconnecting one of said cylinders with said fitting, and a tube interconnecting said fitting with said meter.

References Cited in the file of this patent UNITED STATES PATENTS 

